Field
Aspects of the present disclosure relate generally to equalizers, and more particularly, to an apparatus and method for combining currents from a passive equalizer in a sense amplifier.
Background
A transmitting device transmits a data signal to a receiving device by way of a transmission medium or channel. The transmission medium or channel may be of many different types, such as one or more conductive traces disposed on a printed circuit board (PCB) or substrate, or a communications cable, such as a coaxial cable.
Generally, the transmission medium or channel has a frequency response that is substantially flat with minimal attenuation from low frequency (e.g., DC) up to a certain high frequency (“cutoff frequency”). Above the cutoff frequency, the transmission medium or channel has a frequency response that attenuates a signal substantially monotonically with increasing frequency.
The rate at which data may be sent from a transmitting device to a receiving device via a transmission medium or channel is directly related to the cutoff frequency response of the transmission medium or channel. That is, higher cutoff frequency translates to higher dates; lower cutoff frequency translates to lower data rates.
Often, a receiving device employs an equalizer to effectively increase the cutoff frequency of the transmission medium or channel so as to allow for the transmission of higher data rates. Typically, the equalizer may be configured to have a gain-frequency response that provides a certain gain for frequencies below the cutoff frequency, and a higher gain profile (e.g., a peak) for frequencies above the cutoff frequency. Accordingly, the combined frequency response of the transmission medium or channel and the equalizer is such that the effective cutoff frequency is higher in frequency than the inherent cutoff frequency of the transmission medium or channel.